Pneumatic tool.



No. 662,675. l v Patented Nov. 27, |900. H. LEINEWEBER & G. LEINNGER. PNEUMATIC T005..

(Application filed Mar. 30, 1900.)

t', screwed upon the end of the stem.

U N iTEn STATES PATENT IIIIIGE.

HERMAN LEINEWEBER AND GEORGE LEININGER, OE CHICAGO, ILLINOIS.

PN EUiVlATlC TOOL.

SEECIFICATION forming part of Letters Patent No. 662,67 5, dated November 27, 1900..

Application led March 30, 1900. Serial No. 10,789. (No model-l' To @ZZ whom if; may concer/'71,.-

Beit known that we, HERMAN LEINEWEBER and GEORGE LEIN1NcnR,oitizens of theUnited States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Pneumatic Tools, of which the following is aspeciication.

Our invention relates to improvements in pneumatically-operated tool-holding hammering implements; and our object is to provide certain improvements, more especially in the construction and operation ot the slidevalve and oiling means for the moving parts to render the im pleurent particularly simple, durable, easy running, and well adapted for its purpose.

In the drawings, Figure lis a longitudinal section of the implement; Fig. 2, a section taken on the irregular' line 2 of Fig. l and viewed in the direction of the arrow, and Fig. 3 an enlarged perspective View of the slidevalve.

A is a tubular casing provided in the posi tion shown with a rigid inner annular partition A. In the casing in the position shown are ventAopenings n b c CZ. Extending centrally through the partition A is a guideopeninge for the stem B of a piston or hammer B. Also extending through the partition is a guide-opening ffor a cylindrical slidevalve C. rlhe partition separates the interior of the shell into two chambers A2 A3. Extending through the shell are inlet-ports g h, communicating, respectively, with the chambers A2 A3. The piston B tits closely the inner wall of the casing, and the stem B' ts closely through the opening@ in the partition. On the outer end of the stem portion B/ is a second pistion B2. It is coniined on the stem between a shouldert'and a jam`-nut The piston A is reduced in circumference between its ends to form the annular recess Zt, and the opening@ of the partition is enlarged between its ends to form the annular recess e. In the end of the stem B' is an oil-chamber Z, closed at its outer end by means of a screwplug Z'. Extending from the chamber Z to a point central, or nearly central, of the piston Bis an oil-duct Z2, from the inner end of which branch d ucts Z3 extend to the recess 7c. Branch ducts Z4 also extend from the duct Z2 to register at their outer ends with oil-ducts Z5 in the piston B2.

D is a handle formed with a ring D', which m, communicating through a small port with the recess e'. The chamber is closed by means of a screw-plug m', which passes through the ring D into the shell, and thus fastens these parts together. Extending through the handle is an air-supply passage n, terminating in a chamber n over the ports g Zt. Interposed in the passage n is a valve p, having a stein p extending beyond one side of the handle. The valve p is held normallyin the position'shown to close the passage n by means of a spring p2, and inward pressure against the stem p moves the valve to open the passage n. Extending to the outer end of the passage 'n is a hose q, which communicates withasuitablecompressed-airsupplier. (Not shown.) l

The slide-valve C is cylindrical along its central portion and is cut away at its opposite end portions to produce the semicylindrical recesses fr r. The Valve is provided in the positions shown with the longitudinally-extending recesses S t, which are of the relative lengths shown. In the partition A is a guide-opening e2, enlarged toward its outer end to produce a chamber e3. Extending through the guideopening e2 is a guidepin e, having a head n in the chamber e3. Confined between the head o and a screwplug o2 in the chamber e3 is aspring/UB. The guide-pin o extends into the guide-groovet of the valve C to prevent turning of the latter, the pressure of the pin being rendered yielding by the spring o3 to reduce friction. In the end of the casing A and rigidly secured in place is a tool-receiving tube E,

which fits over and receives the handle portion of a chisel or other tool F.

Starting with the parts in the positions shown the operation will be as follows: When the valve-stem p is pressed inward, compressed air enters through the passage n to IOO end of the piston opens the vent CZ. As the piston B2 nears the outer limit the piston B strikes the end of the valve C and moves it to the position wherein it closes the port 7L and causes the recess rto uncover the port g. When this has occurred, air enters through the port g against the piston B, moving the parts back to the initial position shown, wherein the vent d is uncovered, and the valve C is moved by lthe piston B to close the port g and open the port 7L. The grooves in the valve C is always in communication with the vent-port c, and when the valve is in the position shown the chamber A2 is in connection with the vent-port c through the said groove. When the Valve is moved bythe pistou B to open the port g and close the port h, the groove s opens com munication between the chamber A3 and the vent-port c. The vents a b CZ operate to relieve the chambers A2 A3 of all, or nearly all, pressure above atmospheric when the pistons arrive at the ends of their traverse, while the groove s and port c operate to vent pressure from the chambers while the pistons are moving toward the valve. In each reciprocation of the pistons the piston-hammer B strikes the end of the tool F in the usual manner in tools of this kind. The recesses 7c e materially reduce friction against the piston B and stem and Aafford chambers which are kept filled with lubricating-oil through the ducts described.

The reciprocation of the piston maybe very rapid, and the parts being few and of a construction which renders them particularly strong the device is very durable.

What we claim as new, and desire to secure by Letters Patent, is-

` l.' In a pneumatic tool, the combination of the casing, partition separating the interior of the casing into two piston-chambers, piston-stem movable through an opening in said partition, pistons in said chambers on opposite ends of the piston-stem, air inlet and exhaust portsthrough the casing at the partition, and a slide-valve in the path of and actuated by the pistons, movable through a guide-opening in the partition across the said air inlet and exhaust ports and operating to open communication alternately between said chambers and the said inlet and exhaust ports, substantially as described.

2. In a pneumatic tool, the combination of the casing having the air-vents l) d, partition separating the interior of the casinginto two piston-chambers, pistonstem movable through an opening in said partition, pistons in said chambers on opposite ends of the pis ton-stem, air inlet and exhaust ports through the casing at the partition, and a slide-valve, in the path of and actuated by the pistons, movable through a guide-openingin the partition across the said air inlet and exhaust ports and operating to open communicationv alternately between said chambers and the said inlet and exhaust ports, substantially as described.

3. In a pneumatic tool, the combination of the casing A having the chambers A2 A3, partition A with guide-openings ef, and air inlet and exhaust ports at the partition, pistons B B2, stem BQ slide-Valve C having the end recesses r r', vent-groove s and guide-groove t, and the guide-pin o engaging the guidegroove z5, all constructed to operate substantially as and for the purpose set forth.

4. The combination with the casing A having the partition A', lthe piston B2, circumferentially -recessed piston B, connectingstem B, and the slide-valve, all constructed to operate as described, of an oiling-chamber m in the partition for the piston-stem, an oilchainber Z and oil-duct Z2 in the stem, and branch oil-ducts extending from the duct Z2 to the circumferential faces of the pistons, substantially as set forth.

HERMAN LEINEWEBER. GEORGE LEININGER.

In presence of- D. W. LEE, A. D. BACCI. 

